最低天文潮位計算標準作業程序探討

On the Standard Operation Procedures of LAT Computations

「最低天文潮位」(LAT)是國際海洋測量組織決議所建議採用之「海圖基準」參考潮位面，雖然其定義十分明確，但是並沒有國際規範明確地描述解算過程。本文利用澎湖與新竹驗潮站經基準偏移修正後的長期逐時潮位紀錄資料，進行 LAT 分析，並判定取樣年份、資料長度、分潮選擇及節點潮修正等作業，皆是顯著影響 LAT 結果的主要因子，進而提出 LAT 之計算程序。期待未來可以本研究結果為基礎，建制國內 LAT 之標準作業程序，並作為訂定海圖基準之參考。

"The Lowest Astronomical Tide (LAT) is the reference tide surface to be applied for the establishment of chart datum based on IHO resolution. Although the definition of LAT is very clear, the detailed derivation procedures are not documented yet. In this study, the factors which are related to the derivation of LAT are studied for establishing a Standard Operation Procedure (SOP). Using the long-term tide data from Penghu Station and Hsinchu Station after tidal abnormal being corrected, it is analyzed that the sampling data year, data length, selection of tidal constituents, and nodal correction are the main factors that affect the LAT results. Due to the limitations of existing data, there are still issues that need to be clarified. In the future, the results of this research can be used as the basis for the establishment of Taiwan Chart Datum. "